Does getting a pump or not have much if any correlation at all to how effective you work out has been or how good a certain exercise is ?

A few guys have told me at my gym that they prefer dumbbell upper body work because it gives them more of a pump than barbells do

I am just about the only person at my gym that performs a standing overhead barbell press instead of a seated dumbbell press which gives a much better pump

For my money, there's not much of a correlation.

I can get an excellent pump in the chest and lats from swimming, but I'm not sure how much development this would equate to. Conversely, there are plenty of massively built powerlifters and olympic lifters who seem to acquire muscle without ever doing sufficient reps to get pumped.